Siemens SITRANS L - Connecting; Preparing the Connection

Connecting
5
5.1 Preparing the connection
Safety instructions
Always keep in mind the following safety instructions:
• Carry out electrical connection by trained, qualified personnel authorised by the
plant operator
WARNING
Only connect or disconnect in de-energized state.
Voltage supply
The data for power supply are specified in chapter " Technical data".
Note
Power the transmitter via an energy-limited circuit (power max. 100W) acc. to
IEC61010-1, e.g.
• Class2 power supply unit (acc. to UL1310)
• SELV power supply unit (safety extra-low voltage) with suitable internal or
external limitation of the output current
Keep in mind the following additional factors that influence the operating voltage:
• Lower output voltage of the power supply unit under nominal load (e.g. with a
transmitter current of 20.5mA or 22mA in case of fault)
• Influence of additional transmitters in the circuit (see load values in chapter
" Technical data")
Connection cable
The device is supplied with a fixed connected cable. If an extension is required, a
shielded two-wire cable is recommended.
Shielded cable generally necessary in HART multidrop mode.
SITRANS LR120
Operating Instructions, 08/2020, A5E49829026
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